
Contribution of X-ray absorption spectroscopy to the study of the phase diagram of Fe2O3 compressed by laser shock.
Juan Pintor's PhD defense - December 13, 2024
Abstract
This thesis is devoted to the study of the phase diagram of Fe2O3 under dynamic compression by laser shock. The main objective is to understand the behavior of this material under high pressure and temperature, an important insight for various applications in geophysics, materials science and astrophysics. The experimental methodology relies mainly on in situ X-ray absorption spectroscopy, a technique that enables real-time observation of structural and electronic changes in Fe2O3 during dynamic compression. Complementing the experimental approach, ab initio calculations based on density functional theory (DFT) are carried out. These calculations aim to determine the electronic structures of the different Fe2O3 phases that may appear under compression, and to simulate their X-ray absorption spectra. This approach, combining experiment and theory, provides a deeper understanding of the mechanisms underlying the observed phase transitions, and aids interpretation of the experimental data. This knowledge is aimed at improving our understanding of the behavior of materials in planetary interiors and of geological processes under extreme pressure and temperature conditions.
Jury
- Laurent BERTHE (Directeur de recherche CNRS, PIMM Paris ) - Rapporteur
- Amélie BORDAGE (Chargée de recherche CNRS, ICMMO Orsay ) - Rapporteure
- Franck VIDAL (Professeur des universités SU, INSP Paris ) - Examinateur
- Tommaso VINCI (Ingénieur de Recherche CNRS, LULI Ecole Polytechnique ) - Examinateur
- Delphine CABARET (Professeur des universités SU, IMPMC Paris ) - Encadrante de thèse
- Marion HARMAND (Chargée de Recherche CNRS, PIMM Paris ) - Encadrante de thèse